A previously unidentified Chorioptes species infesting outer ear canals of moose (Alces alces): characterization of the mite and the pathology of infestation

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Abstract

Background

During the past decade, Chorioptes mites occupying the outer ear canals have been a common finding at routine necropsies of moose ( Alces alces) in Sweden, but neither the taxonomy of the mites nor lesions from the infestation have been investigated. In this study, the mites are characterized by morphological and molecular techniques, and the histopathology of the skin of the outer ear canal is described.

Methods

External auditory meatuses from 53 necropsied moose were examined for the presence of Chorioptes, and samples from outer ear canals were taken for histopathological and microbiological examination. A proportion of the mites from each moose was identified to species. The DNA was extracted from mites from three moose, and their ITS-2 sequences were determined; these sequences were compared phylogenetically to sequences from other Chorioptes taxa.

Results

Chorioptes mites were found in 43 (81%) of the 53 moose. The mites had morphological and genetic characteristics distinct from those of C. texanus and C. bovis, the two species generally accepted within the genus. Morphology also did not argue for a diagnosis as C. crewei, C. mydaus or C. panda. On histopathology, lesions were characterized by a hyperplastic perivascular to interstitial dermatitis with epidermal hyperkeratosis and crust formation. Dermal inflammatory infiltrates were composed of mixed T- and B-lymphocytes, plasma cells and macrophages, whereas eosinophils were notably uncommon. Staphylococcus aureus was grown from the infested epidermis of five of 14 examined moose.

Conclusion

Chorioptes mite infestation was frequently detected in the outer ear canals of moose in Sweden. The mites were evidently pathogenic, being associated with inflammatory lesions of the external auditory meatus. Our studies indicate infestations with a previously undescribed Chorioptes species.

Related collections

Most cited references 41

Record: found
Abstract: not found
Article: not found

The Parsimony Ratchet, a New Method for Rapid Parsimony Analysis

Kevin Nixon (1999)

0 comments Cited 411 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: not found
Book: not found

PAUP: Phylogenetic Analysis Using Parsimony ( and Other Methods)

D. L. SWOFFORD, DL Swofford, D. SWOFFORD … (2003)

0 comments Cited 72 times – based on 0 reviews

Bookmark

Record: found
Abstract: found
Article: not found

Evaluating the performance of a successive-approximations approach to parameter optimization in maximum-likelihood phylogeny estimation.

David Swofford, Zaid Abdo, Timothy J. Sullivan … (2005)

Almost all studies that estimate phylogenies from DNA sequence data under the maximum-likelihood (ML) criterion employ an approximate approach. Most commonly, model parameters are estimated on some initial phylogenetic estimate derived using a rapid method (neighbor-joining or parsimony). Parameters are then held constant during a tree search, and ideally, the procedure is repeated until convergence is achieved. However, the effectiveness of this approximation has not been formally assessed, in part because doing so requires computationally intensive, full-optimization analyses. Here, we report both indirect and direct evaluations of the effectiveness of successive approximations. We obtained an indirect evaluation by comparing the results of replicate runs on real data that use random trees to provide initial parameter estimates. For six real data sets taken from the literature, all replicate iterative searches converged to the same joint estimates of topology and model parameters, suggesting that the approximation is not starting-point dependent, as long as the heuristic searches of tree space are rigorous. We conducted a more direct assessment using simulations in which we compared the accuracy of phylogenies estimated using full optimization of all model parameters on each tree evaluated to the accuracy of trees estimated via successive approximations. There is no significant difference between the accuracy of the approximation searches relative to full-optimization searches. Our results demonstrate that successive approximation is reliable and provide reassurance that this much faster approach is safe to use for ML estimation of topology.

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Author and article information

Journal

Journal ID (nlm-ta): Acta Vet Scand

Title: Acta Veterinaria Scandinavica

Publisher: BioMed Central (London )

ISSN (Print): 0044-605X

ISSN (Electronic): 1751-0147

Publication date Collection: 2007

Publication date (Electronic): 10 September 2007

Volume: 49

Issue: 1

Page: 21

Affiliations

[1 ]Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7028, 750 07 Uppsala, Sweden

[2 ]Bavarian Health and Food Safety Authority, Veterinärstrasse 2, D-85764 Oberschleissheim, Germany

[3 ]Institute for Comparative Tropical Medicine and Parasitology, Ludwig Maximilian University, Leopoldstrasse 5, D-80802 Munich, Germany

[4 ]Department of Wildlife, Fish and Environment, National Veterinary Institute (SVA), Box 7073, 750 07 Uppsala, Sweden

[5 ]Department of Parasitology, National Veterinary Institute (SVA), Box 7073, 750 07 Uppsala, Sweden

Article

Publisher ID: 1751-0147-49-21

DOI: 10.1186/1751-0147-49-21

PMC ID: 2040144

PubMed ID: 17825115

SO-VID: 408374d7-807f-463f-8471-2f7f7f259367

License:

This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.